#include "doll.h"
#include <bits/stdc++.h>
using namespace std;
int N, P = 1, switches = 1;
vector<int> X(1<<20), Y(1<<20);
bool state[1<<20];
int build(int l, int r) {
if (l >= r) return 0;
if (r < P - N) return -1;
int mid = (l + r) / 2, ts = switches++;
X[ts - 1] = build(l, mid);
Y[ts - 1] = build(mid + 1, r);
return -ts;
}
void point(int i, int j) {
int &a = state[-i] ? Y[-i - 1] : X[-i - 1];
state[-i] = !state[-i];
if (!a) a = j;
else point(a, j);
}
void create_circuit(int M, vector<int> A) {
N = A.size();
while (P < N) P *= 2;
build(0, P - 1);
for (int i = 1; i < N; i++) point(-1, A[i]);
if (N & 1) point(-1, -1);
point(-1, 0);
X.resize(switches), Y.resize(switches);
vector<int> C(M + 1, -1);
answer(C, X, Y);
}
